How do I know if a broker is legitimate?

Check regulatory databases
In the US, visit FINRA's BrokerCheck or the SEC's Investment Adviser Public Disclosure database. In the UK, check the FCA register. Canada has IIROC. These databases show whether a firm is registered, what licenses they hold, and any disciplinary history.
Verify company details
Confirm the broker's legal name matches their website. Look for a physical address (not just a phone number) and verify it independently. Scams often use names similar to legitimate firms or refuse to provide addresses.
Test customer service
Contact the broker with questions about account setup and fees. Legitimate firms respond clearly and consistently. Be wary of pressure to deposit money quickly or vague answers about how they make money.